The next time you're humming your favourite tune on the way to work in the car, your CD player could strike up and begin to play the more accomplished version to accompany you, if the work of a UCD student makes it to the market.

Mr Neal O'Kennedy, a final year computer science student at UCD, has developed a computer system that will retrieve a piece of music from a database using the whistling or humming of its melody as a cue.

With online sales of CDs growing rapidly, the commercial demand for such a system should be huge with many people unable to remember the name of a song or album they heard on the radio or television.

Mr O'Kennedy said that it grabs the tune by extracting fundamental frequencies from it, transcribing them into musical notation and matching them to the frequencies of a tune from the database.

The music recognition system, which uses acoustic input as a method of referencing music, has several practical applications.

The system could be used for an in-store query system in a sheet-music shop to find a piece of music for a customer.

Mr O'Kennedy said that the retrieval system would allow the key of a tune hummed by the customer to be changed to match it to the desired song.

For the ever more stressed commuter, it could offer an acoustic interface on their in-car CD player for music recordings.

Rather than rooting through the CDs strewn around the car, they could just hum the tune of their favourite song to get to listen to the desired CD or track.

It might also reduce road accidents, because the driver would not have to fiddle with buttons and take his or her eyes off the road to operate the CD player's controls.

The system, which was developed under the supervision of Dr Arthur Cater, can be customised to each user so that the tune he or she hums may be from any part of the score.

Mr O'Kennedy said he believed it was the first such system to be targeted at the retrieval of music and would not be costly, requiring only some memory capacity, a signal processor and a microphone.

The spread of digital media, and in particular the widespread use of the MPEG format to send and store still images, audio and video has been accompanied by a parallel growth in piracy of these media.

However another UCD student, Mr David Greene, has developed a new method of watermarking digital media by embedding invisible information in MPEG-2s to protect the copyright of the originators.

The process is the culmination of more than six years work by UCD scientist, Dr Gueneole Silvestre and Dr Liam Dowling of Trinity College, Dublin who investigated the prevention of digital media piracy by the embedding invisible data.

As digital video disk is expected to take over from analogue video machines, the market for such a product is set to increase significantly over the coming years.

Mr Greene, a final year computer science student, said that interactive video on demand (VOD) applications will be introduced enabling people to individually select movies that they want to watch when they want to.

An increasing number of videos and films are now being recorded in digital format with the next instalment of Star Wars being filmed using digital cameras. Increases in bandwidth are facilitating the move into the new medium.

Mr Greene developed an MPEG-2 encoder, decoder and player which he says is reliable, robust and invisible to the human eye.

Mr Greene embedded the watermark by applying an imperceptible modification to the data which can indicate the copyright owner, or if applied to individual copies of the video, the identity of the receiver of each copy.

This will allow illegally reproduced copies to be traced back to the receiver of each copy.

Such watermarks should make it impossible to remove embedded information without severely damaging the data.

Many of the new digital applications such as digital television and video on demand, use MPEG-2 to get the needed compression for transmission or storage.

Mr Greene said that Java code could be embedded in a video stream which would make the interface more interactive by making links or icons to access the Internet pop up as the video is playing.

Several Internet companies have expressed interest in the technology and UCD researchers intend to continue developing the area of research.

The area of watermarking for digital multimedia has not been investigated to any great extent and Mr Greene said that the system would not be costly. He said it would take only a slight modification of software to embed the invisible data.

As the electronic components needed for digital media become more powerful, their cost decreases rapidly, and as the Internet becomes more popular, the market for such a process will grow and grow.